As a result of increasingly strict environmental legislation, exhaust gas treatment systems allowing soot particles existing in combustion exhaust gases to be filtered out or eliminated are gaining in importance. In order to check or monitor the functionality of such exhaust gas treatment systems, sensors are needed which allow the instantaneous particulate concentration existing in the combustion exhaust gas to be accurately determined even in extended operation. In addition, sensors of this type should allow the load of diesel particulate filters, for example, provided in an exhaust gas system, to be predicted in order to achieve a high degree of system reliability, thus allowing the use of more cost-effective filter materials.
German Patent document DE 102 44 702 A1 discusses a sensor for detecting substances in a fluid stream which includes two measuring electrodes at a distance from each other which are exposed to the combustion exhaust gas to be examined. One of the electrodes is connected to a high-voltage source, so that a voltage between 1 kV and 10 kV is applied to the electrode.
Dielectrically hindered discharges occur between the measuring electrodes, the current between the measuring electrodes being correlated with the number of particles present in the gas space between the measuring electrodes. The disadvantage of this type of particulate sensor is its relatively complex and therefore cost-intensive design.
An object of the exemplary embodiment and/or exemplary method of the present invention is to provide a sensor for determining the particulate concentration in gas mixtures that exhibits a high degree of accuracy of the measuring signals obtained and yet may be manufactured cost-effectively.